Marine Producers
Phytoplankton
Phyto (plant) planktos (wandering)
Microscopic plants that live in the ocean Over 10,000 species of phytoplankton Foundation of the marine food chain 2/3 of all the photosynthesis that takes place
is in the oceans
Diatoms
Marine producers Are unicellular Enclosed by cell walls made largely of silica Aggregate into chains or star-like groups
Algae
Simple aquatic organisms Eukaryotic Photosynthetic
Photosynthesis vs. Respiration
Photosynthesis– Occurs in chloroplasts– Solar energy captured by chlorophyll– Oxygen by-product
Sunlight + CO2 + H2O ----> O2 + Sugars
Respiration– Occurs in mitochondria– Release of energy from breaking down sugars– Carried out by both autotrophs and heterotrophs
Sugars + O2 ----> CO2 + H2O + chemical energy
http://www.cellsalive.com/cells/plntcell_archive.htm
Macroalgae a.k.a. macrophytes
Popular name- seaweed Multicellular Eukaryotic Lots of variation in structure and appearance Three types of seaweed
– Green algae– Brown algae– Red algae
General Structure
No true leaves, stems, or roots Thallus- Body structure Blades- leaf like structure
– Main photosynthetic regions Pneumatocysts
– Gas filled bladders which help keep blades near sea surface maximizing exposure to sun
Stipe– Stem-like structure which provides support
Holdfast– Root-like structure which attaches thallus to the bottom
Do not penetrate through the sand or mud Do not play a significant role in absorption of water and nutrients
Macroalgae Structure
Chlorophyta- Green algae
Occur in both Freshwater and Marine environments
Bright green in color because chlorophyll is not masked by other pigments
Ulva- Sea lettuce Codium fragile- Dead man’s fingers Over 8,000 species 90% are freshwater / 10% saltwater
Ulva Lactuca Kingdom: ProtistaPhylum: ChlorophytaClass: UlvophyceaeOrder: UlvalesFamily: UlvaceaeGenus: UlvaSpecies: Lactuca
Genus Ulva- Sea Lettuce
Codium fragile- Dead man’s fingers
Kingdom: Protista
Division: ChlorophytaClass: BryopsidophyceaeOrder: CodialesFamily: Codiaceae
Genus: Codium
species: fragile
Phaeophyta- Brown Algae
1500 species Predominantly marine Range in color from olive to dark Common in rocky shores Brown due to yellow-brown pigments
– Fucoxanthin Pigment in brown algae that dominates over chlorophyll
Phaeophyta
Rockweeds and Kelps Kelp forests play an important role in marine
ecology by providing food and shelter for marine organisms
Some species grow very large– Nereocystis- Bull Kelp’s stipe can be up to 30
meters long– Macrocystis- Stipes can be up to 100 meters long
These giant kelp are estimated to grow 50cm per day!!!!
Phaeophyta
Kelp Forest Temperate Rain Forest
Rhodophyta: Red Algae
More species than of other two types– 4,000 species – Only a few fresh water species
Red pigments: phycobilins– These pigments mask chlorophyll
Common in rocky shorelines Coralline Algae
– These species deposit calcium carbonate within their cell walls
– Are actively involved in the formation of coral reefs
Rhodophyta
Reproduction In Algae
Asexual reproduction is common– Vegetative reproduction– Fragments of thallus can grow into new organisms– Some reproduce by spores which disperse to new locations
Sexual reproduction– Production of gametes– Spores and Gametes are produced by meiosis
Economic Importance
Used as a food sources in China, Japan, and Korea Used as fertilizers, and in animal feeds Phycocolloids are used in food processing for their
ability to form viscous suspensions– Algin- a phycocolloid that is used in ice cream, cheese, and
baked goods. Also used in shampoos, paints, and cosmetics
– Carrageenan- used as an emulsifier. Gives body to dairy products and pudding
– Agar- Used to form jellies as a thickening agent. Also used as a medium to grow bacteria and molds.
Marine Flowering Plants
Kingdom Plantae Angiosperms: aka flowering plants Dominant land plants Few species live in marine environments Have true roots, stems, and leaves All have flower as dominant reproductive
organ
Seagrasses
Resemble grasses, but are not grasses at all Pollen for reproduction is carried by water
currents Eelgrass
– 50-60 species– Found in shallow coastal waters– Have ribbon-like leaves– Common in oxygen poor sediments
Turtlegrass
Eelgrass
Salt-Marsh Plants
Cordgrasses– Live on land, but are salt
tolerant– Not completely submerged– Become submerged during
high tidal periods
Mangroves
Trees and shrubs living on tropical shores Land plants that tolerate salt Grow in mud bottom estuaries, and coastal
lagoons Arched roots trap sediment and cause more
land to build up expanding the colony toward the sea
Red Mangrove